Drag clam



May 29, 1928.

H. T. DUNBAR DRAG CLAM 2 Sheets-Shet 1 Original Filed June 13, 1925 o c a Q g r? a mum May 29, 1928.

H. T." DUNBAR DRAG- CLAM 2 Sheets-Sheet 2 Original Filed June 13, 1923 M a w J H f 05 0 o 0 o v 7. Z 5 z v Z Ho o W Q j III-Hill III llnllll Quorum: 5

Patented May 29, 1928.

- UNITED, STATES v PATENT OFFICE.

HARRIS r. nunma or BUFFALO, NnwYonx.

more emu.

Original application filed J une 13, 1923, Serial No. 645,203. Divided andtliis 1925. Serial No. 38,958.

This invention relates to a drag-clam which 1s more particularly designed for picking up or gathering loose material and transferring the same from one place to-another, as for instancewhen excavating or removing soil, gravel or the like in constructing the foundations of railways, the

beds of canals and similar work.

The object ofthis invention is the provision of improved means for automatically connecting and disconnecting the rear end of the scoop with the free end of the arm whichactuates the lid at the front end of the scoop during the operation of emptying the scoop and lowering the same on the ground. 7

This application is a division of an application for United States patent filed by myself June 13, 1923, Serial Number 645,203. In the accompanying drawings 1 Figure 1 is a vertical longitudinal section of a drag-clam embodying my invention.

Figure 2 is a rear elevation of the latch employed for holding the operating arm in.

the position in which the scoop or bucket is in its open position.

Figure 3 is a top plan View of the dragmg arm 10 which preferably comprises two clam shown in Fig. 1.

Figure 4 is a longitudinal sectional elevation showing a modified form of my invention.

Figure 5 is a top plan view thereof.

Similar characters of reference indicate corresponding parts through the several views. a

The body of this drag-clam is constructed in the form of a scoop which comprises a horizontal bottom 1, two longitudinal side Walls 2 projecting upwardly from opposite longitudinal edges of the bottom, and a rear transverse wall 3 projecting upwardly from the rear edge of the bottom and connecting the rear ends of the side Walls, thereby producing a bucket or box which is open at the top and also has its front end open, so as to form an inlet mouth for the scoop.

In order to strengthen the mouth of this scoop when being hauled over or into any material, a. lip 4 is provided to cause the material to be separated from the mass and directed into the scoop, the front edges of the bottom and side walls of this lip 4 are constructed. in the forms of a blade orcutter so as to enable the same to enter the material easily. After the scoop or bucket has been hauled intothe material su'fliciently to gather ing tranversely throughcorresponding openings or hearings in the upper front parts of the scoop s de and the rear ends of said side pieces, and a transverse plate or Shutter '7 connecting the front ends of the side pieces 5 and provided at its lower edge with a transverse strengthening lip or bar 8. While the scoop isresting on the material and the lid is turnedupwardly into its open position, the drag-cla1n is dlfi-WII'OI hauled forwardly by a drag or pull line, 9, connectedwith the lid and extending to a drum forming part of the dredging apparatus with which this drag-clam is associated.

Secured to the lid and pro'ecting rearwardly from the pivot thereof is an operatrearwardly converging side bars which are secured at their separated inner or front. ends to the side pieces of the lid while their rear ends are connected with each other in any suitable manner.

Means are provided for automatically locking the lid in its open position after the drag-clam has been shifted into a position in ap'plication lled J'une 18,

a loadvwithin and ahead the front end or jecting tall 41 adapted to engage with the lower edge 32 of the head 32 below the guard sheave 29 which forms a stop for the same. The drag or pull line 9 connects with the outer lower corners of the lid or shutter 7 and the dump line 31 connects atits rear end with an eye 31 on the inner rear corner of the scoop and passes around a \wall El oi the scoop while the hoisting; fall attached atits lower end to the free end of the operating arm and carries at its upper end a sheave 26 around which the hoisting line or fall 23 passes. The dump line 31 at times also passes around the sheave 29.

In thisconstruction, the arm 10" rests on" a' stop formed byupper edge or the rear 23 is slackened and the scoop is eing dragged forwardly by the pull line 9 and the latch 36 is disconnected as shown in Fig. 1., Later as thescoop is turnedby the dump line .31? into its opened position with itsrear wall 3i uppermost, the operating arm 10 approaches the rear wall 01 the scoop, the looking latch loop 36, being held in proper posie tion by the tail 41 against the stop 32 will pass beyondnhook an and engage with the same when the drag-clam returns to .the po sition in which its rear wall '3. is uppermost and the lid has been. swung into an open,; position. Thereafter, slackening of the hoisting iall'23 as shown in Fig; 1 will againpermit the locking latch loop 36 to swing by gravity away from. the locking hook-34" to permit subsequent closing of the lid by an upward pull of the hoisting fall 23. when sufficient material has been gathered into the scoop during its forward movement by the pull line 9. V v i a The construction and operation of the dragclam shown in Figs. 4 and 5 is substantially the same as that shown in Figs.

1 and 3 with the exception that in Figs. 4 and 5 the sheave 15 which receives the dumping line 31 and the sheave 26 which receives the hoisting line 23 are both mounted in a special integral casing 21 which is connected by a linkageQZ with the free end of the operating arm 10*.

As the operating arm is lifted by the hoisting line 23 the lid is closed to confine the load in the scoop and at this time the dump line 31 engages the guard sheave 29 lid and provided with a stop face adapted to engage the stop face of said rear wall, a

hook arranged on the rear side of said wall and having a downwardly facing mouth, and a locking latch having a bifurcated hub l straddling said arm and pivoted thereto, a loop dependingfrom said hub and adapted to engage said hook and a tailprojecting forwardly from said'hub and adapted to engage said stop face onthis wall.

HARRIS T. DUNBAR, 

